>> A firmware replacement for the BIOS does not need to worry about
>> floppy drives, hard drives, optical drives, usb devices, isa
>> devices, pci devices and pci express drives, etcetera, because
>> those live on buses, which the kernel can detect. It would need
>> a device tree to inform the kernel of what buses are available,
>> but that would be specific to a given board, rather than what is
>> attached to it. If the end user makes hardware changes, the
>> kernel should be able to handle that, with the exception of
>> changes involving RAM, which I believe go into the device tree.
>
> I take it the above statement is based on the kernel being
> directly placed within the BIOS/firmware/nvram on the board, such
> that you couldn't boot anything else but that kernel?

That is correct.

> Otherwise I don't see how you could get away with the BIOS not
> worrying about all those devices.. IE, I don't forsee many general
> x86 users giving up their ability to boot off usb stick or cdrom or
> pxe based on a boot-time bios choice, or to boot windows or
> alternative linux kernels (which could be located who knows where)
> at whim. And I don't see how an alternative BIOS would be able to
> provide this ability without dealing with all the things Duncan
> mentioned...